Conveyer slot seal



J. C. WOODSON CONVEYER SLOT SEAL June '7, 1932.

Filed Feb. 28, 1951 lfllflllllli A /fu/ lNvgN'roR James 6. Woodson.

WITNESSESI ATTORNEY Patented June 7, 1932 UNITED STATES JAMES C. WOODSON,

OF M ANSFIELD, OHIO, ASSIGNOR TO WESTINGHOUSE ELECTRIC &

MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA CONVEYER SLO T SEAL Application filed February 28, 1931. Serial No. 518,929.

My invention relates to horizontal-chamber overhead-conveyer furnaces and particularly to slot-sealing means for such furnaces.

An object of my invention is to provide a relatively simple, compact and eiiicientstationary sea-ling means for a slot in the roof of a conveyer-type furnace.

In practicing my invention, I provide, in combination with a furnace embodying refractory Walls including one or more heated chambers, an endless conveyer including a chain or belt moving continuously over the top of the furnace, the roof of the furnace being provided with a slot therein, extending longitudinally of the structure, to permit depending material-supporting rods suspended from the conveyer chain to move material to be heat treated through the furnace chamber, the device embodying my invention being constituted particularly by novel means for closing the slot, including resilient metal plates pivotally mounted at the top of the furnace structure, one set at each side of the slot and spring pressed against a substantially continuous portion of the moving conveyer chain.

In the drawing,

Figure 1 is a view, in lateral section, through a furnace with `which is associated the device embodying my invention.

Fig. 2 is a fragmentary view, in vertical lat-eral section on an enlarged scale, and il-` lustrating particularly the device embodying my invention,

Fig. 3 is a fragmentary View, in side elevation, of a device embodying my invention,

Fig. 4i is a fragmentary view of a structure of modified form comprising a part of my invention, v

Fig. 5 is a partial sectional view of the device shown in Fig. 4, taken on the line V-V thereof, and,

Fig. 6 is a view, in perspective, of a single slot-closure plate.

The slot closure constituting my present invention is particularly applicable to conveyer-type furnaces of the general kind disclosed and claimed in my copending appiication, Serial No. 436,369, filed March 17, 1930, and assigned to the Westinghouse Electric &

Manufacturing Company, and certain of the details illustrated in the present drawings are substantially like those disclosed in the above identified application, to which reference may be had for the details of construction of those parts of the furnace not particularly claimed in the present application. Only so much description of these parts will be given as Will make clear the general constructional details of the furnace and the cooperation therewith of the details constituting my present invention.

Referring particularly to Fig. 1 of the drawing, I have there illustrated, in lateral section, a double-chamber furnace structure resting on a base 11 of concrete and including a metal bracing-and-supporting structure 12 which includes vertically extending buck-stays of structural steel and horizontal top cross members of the same General kind, all secured together in any desired or suitable manner. A meta-l side wall 13 is provided, as well as inner Walls 11i, which may either be monolithic or may be built up of bricks or blocks of a suitable refractory hightemperature-resisting material to constitute the floor, side walls and central wall. Granular refractory heat-insulating material 16 is located in the space between the portion 14 and the sheet-metal wall 13.

A plurality of slabs 17, of fire clay, are located on the upper ends of the portion 14 and of the central wall and are of such shape as to interlock in side-by-side relation, and are maintained in proper operative position by masses 18 of concrete, which are covered, at the top, by an extension of the granular electricand heat-insulating material 16.

A slot 19 is provided in the roof structure above each of the chambers 21 and 22, and the structure of the furnace walls is such as to insure that the dimensions and location of the slot, relative to the metal frame structure 12, shall remain substantially the same, irrespective of the operating conditions of the furnace. To this end, the ends o-f the slabs 17 are resiliently supported by rods 23 having helical springs 24 at the top thereof, these rods and springs being supported from lugs 26 which, in turn, are respectively supported by additional portions of the metal framework, including, particularly, vertically depending structura-l steel members 27 and 28 and cross-pieces 29, 31, 32 and 33.

I have illustrated a particular heating means for the two chambers 21 and 22 as including metallic strips or wires 34 suitably supported adjacent to, but clear of, the side walls and iioor heating elements 36 covered by oor plates 37 and, as the use of my invention is not limited to electric heating elements, I desire it to be understood that the illustration of these resistors is for illustrative purposes only and that any suitable or desirable heating means, electric, gas, oil or solid fuel may be used.

It is to be further understood that, as was hereinbefore noted, the specific disclosure is for illustrative purposes only and that reference may be had to my hereinbefore mentioned copending application for further details of construction.

The device embodying my invention is illustrated in Figs. 2 to 6, inclusive, of the drawing and includes, more particularly, substantially stationary means for preventing or reducing, as much as possible, the outflow of hot air through the respective slots 19 during the operation of the furnace. Material to be heat-treated, such, for instance, as range plates to be enameled, are carried through either or both of the furnace chambers 21 and 22 by being suspended from one or more hooks 38 which are suspended from a cross-piece 39 carried by metal support-ing rods 41 which, in turn, are supported and moved by a continuous conveyer chain illustrated generally only at 42 in Fig. 1 of the drawing, as being supported by rollers 43 moving on a suitable track, in a manner well known in the art. In order to permit of continuous movement of the conveyer chain 42 and, particularly, of the material being enameled o-r otherwise heat-treated, it is necessary that the ends of the furnace structure be open, and it is apparent that, if no means were provided to prevent or reduce the escape of heat through the slot, a relatively large amount of heat would be lost by heated air flowing out through the slot or slots 19.

In order to reduce this outflow of heated air, I provide a pair of substantially continuous metal walls 44, one of these being located at each side of each slot 19 at the top of the furnace structure. Resilient metal sheets 46, each bent to substantially arcuate shape in lateral section, are pivotally mounted on the respective walls 44, as by having their lower edges riveted or screwed against angle-bar members 47, one surface of which is provided with a knife-edge pivot 48, substantially as shown in Fig. 6 of the drawing. Bolts 49 extend through suitable openings in the wall 44 and, in one portion of the anglebar member 47, a spring 50 is located around the bolt 49 to yieldingly press the upper end of the arcuate sheet 46 toward a portion of the conveyer chain now to be described.

The material-supporting bars or rods 41 are preferably made of rectangular shape in lateral section and they are, of course, suspended from the chain 42 at spaced intervals. The space between the material-supporting rods 41 and intermediate depending bars 51 (see Fig. 3) is filled by horizontallyextending bars 52 of the same thickness as the bars 41 and 51 and having pivotal connection therewith, as by chain links 53, as shown in Fig. 3 of the drawing. The upper edges of the plates 46 will, therefore, be spring pressed against an articulated and substantially continuous structure which is moving as long as the conveyer chain is moving. The degree of compression effected by the respective springs 50 may, of course, be so adjusted that the compressive force of the spring 50 around the bolt 49 and located above the knife edge 48, will be just sufficient to cause the upper end of the plates 4G to engage closely the bars 41 and 51 and the intermediate bars 52 but not to cause excessive pressure and friction therebetween, and hence it is possible to obtain a substantially tight slot closure without excessive friction and wear on the copending parts, certain of which Y may be hardened, in a manner well known in the art, to reduce the wear thereof.

Referring to Figs. 4 and 5 of the drawing, I have there shown a somewhat different support for the horizontal bars 56, which extend between the material supporting bars 41 and the intermediate bars 51. The bars 41 and 51 are provided with lateral extensions 57, and the lower ends of the bars 51 are widened, as shown in Fig. 4, and pivot pins 58 are secured therein to t into openings adjacent to the ends of the horizontal bars 56. This provides a flexible structure in substantially the same manner as does the device shown in Fig. 3 of the drawing, so that the conveyer chain may move around a sheave at the ends of its travel at either end of the furnace, in a manner already well known in the art.

Various modifications of my invention may be made without departing from the spirit and scope thereof, and I desire, therefore, that only such limitations shall be placed thereon as are imposed by the prior art or are set forth in the appended claims.

I claim as my invention:

1. In combination with a heated furnace having a slot in the roof, a conveyer chain travelling above the roof having spaced material-supporting rods depending therefrom and moving in said slot, and bars extending horizontally between said depending rods and pivotally connected thereto, of stationary resilient plates in end-to-end relation at each side of the slot with their upper edges frictionally engaging the rods and horizontally extending bars, and resilient supporting means for the lower edges of the plates cooperating therewith to prevent escape of heat through the slot.

2. In combination with a heated furnacehaving a slot in the roo-f, a conveyer chain travelling above the roof having spaced material-supporting rods depending therefrom and moving in said slot, and bars extending horizontally between said depending rods and pivotally connected thereto, of stationary resilient plates in end-to-end relation at each side of the slot with their upper edges frictionally engaging the rods and the horizontally extending bars, cooperating means on said furnace and on said plates for pivotally supporting the resilient plates on the furnace and for causing the upper edges of the plates to be spring-pressed against the rods and the horizontally-extending bars.

3. In combination with a heated furnace having a slot in its roof, a conveyer chain moving above the roof and having spaced material-supporting rods depending therefrom and moving in the slot, of means for preventing escape of heat through said slot, said means including cooperating sets of plates, of arcuate shape in lateral section, each having one edge pivotally mounted on the furnace and having the other edges eX- tending upwardly and toward each other to engage the depending rods, and plates of substantially the same thickness as the rods located therebetween and moving therewith.

4. In combination with a heated furnace having a slot in its roof, a conveyer chain moving above the roof having spaced material-supporting rods depending therefrom and moving in the slot, and means for preventing escape of heat through said slot, said means including cooperating sets of oppositely-extending plates of arcuate shape in lateral section, the plates of each set being located in closely adjacent positions above said slot and having their upper edges springpressed against said rods, and filler bars supported by and between the rods to maintain the separation of the arcuate plates and prevent escape of heat through the roof slot.

In testimony whereof, I have hereunto subscribed my name this 14th day of February7 1931.

JAMES C. WOODSON. 

